This application claims the priority of German Patent Application DE 102 00 953.7 filed Mar. 6, 2002 which is incorporated herein by reference.
The invention relates to a method for measuring wear on internal barrel surfaces, particularly of weapon barrels, as well as to a device for realizing this method.
As a result of hot propellant charge gases and/or friction between the projectile and the internal surface of the respective weapon barrel, the latter is subjected to erosive and/or abrasive wear that affects the service life of the respective weapon barrel. The weapon barrels must therefore be checked from time to time for wear. According to a previously proposed solution, the surface of the barrel to be checked must be scanned mechanically to measure the wear. However, this method has the disadvantage of being extremely time-consuming and relatively imprecise.
It is the object of the invention to provide a method for determining with extreme accuracy the wear on the internal surfaces of barrels and, in addition, provide a device for realizing this method.
This object is achieved according to a first aspect of the invention by a method that is essentially based on the non-contacting scanning of the internal surface of the respective barrel to be checked with the aid of a light-spot triangulation sensor and determining of the respective distance between the internal surface and the barrel axis for selected sensor positions. The contour of the internal surface of the respective barrel can subsequently be inferred from the detected distance changes. In the process, it has proven advantageous if the measured distance values are displayed on a monitor in the form of a C-image, wherein different radial distance ranges can be characterized with different colors so that the faulty surface regions can immediately be detected optically.
The above object generally is achieved according to a second aspect of the invention by a device for measuring the internal surface wear that comprises a manipulator that can be inserted into the respective barrel and contains a light-spot triangulation sensor, as well as a control unit required for actuating the manipulator and a signal evaluation device that is connected to the sensor. The manipulator is provided with a housing that can rotate around the barrel axis and contains an axial guide that is connected so as to rotate along with the housing. The triangulation sensor is arranged so as to be displaceable in longitudinal direction along this guide. In addition, the rotating housing has a gap-type opening that extends in the direction of the barrel axis. The light emitted by the light source of the triangulation sensor can travel through this opening to the outside and the light reflected by the internal barrel surface can travel back through the opening to the detector of the sensor. The rotating housing supports itself at both ends in pivoting brackets or bearings that can be secured, with radially displaceable holding elements, on the internal barrel walls and permit an automatic centering or the manipulator inside the barrel.
Supporting the manipulator on both sides inside the barrel ensures that the triangulation sensor can be moved relatively precisely along the barrel axis during the axial displacement. In addition, it results in a quiet running of the housing during the rotation around the barrel axis. Finally, the rotating housing protects the triangulation sensor against mechanical damage.
A laser diode is preferably used as a light source for the light-spot triangulation sensor because it has better radiation characteristics as compared co other light sources, e.g. light-emitting diodes (which can also be used) and permits a more compact design. Owing to their high sensitivity, CCD line sensors (CCD-charge coupled device) in particular have proven useful an detectors for triangulation sensors.
Further details and advantages of the invention become evident from the following exemplary embodiment explained with the aid of the figures.